Roof Position Limit Switch (Position No. 1 & 2)
OEM Part Number
84742-24050 — Switch, Slide Roof Limit (For Roof Position No. 1 & No. 2). No known supersession. [Verified — OEM catalogue and Nengun Performance]
What It Is
A small microswitch that detects the roof panel position at positions 1 and 2 (closed and intermediate states). Located in the passenger side convertible frame arm assembly. The 89720-24010 Sliding Roof Control ECU reads this switch to confirm the roof has reached the correct position during the open/close cycle. Part of the Retractable Hardtop system.
When this switch fails, it triggers DTC B2523 (Roof Position Switch No. 1 Malfunction). [Probable — documented repair on ClubLexus]
Fitment
All 2002-2010 Lexus SC430 (UZZ40). [Verified]
Related Switches
| Part Number | Function |
|---|---|
| 84742-24050 | Roof Position No. 1 & 2 (this part) |
| 84742-24060 | Roof Position No. 3 |
| 84742-24080 | Link Assembly Wiring — rear body mounted, right upper |
| 84742-24090 | Link Assembly Wiring — additional position |
[Verified — OEM catalogue part numbers]
Aftermarket Alternatives
None known specific to SC430. However, this is a generic microswitch form factor — a knowledgeable auto electrician may be able to source a compatible replacement. [Unconfirmed]
Where to Buy
New OEM
- LexusPartsNow: Available. Price not displayed in research but expected to be $25-60 USD based on similar Lexus switches. [Reported — estimated]
- Nengun Performance: Listed as available for Toyota/Lexus. [Verified — listing found]
- MyLParts: Listed as available. [Verified — listing found]
Used
- Generally not worth buying used — these are small, cheap parts. Buy new.
Installation Notes
- Located in passenger side frame arm assembly [Probable]
- Access with roof in open position [Probable]
- 4mm socket for mounting screw [Probable — documented repair]
- 2-wire plug connector [Probable]
- Mounting screw may be corroded — use precision tools to avoid rounding [Reported]
- No need to disassemble roof, rear window, or rear shelf [Probable]
Related Faults
- Hardtop Position Switch Failure — Full diagnostic and repair guide
Sources
- LexusPartsNow OEM catalogue
- ClubLexus forum: “lexus sc 430 roof b2523” (documented repair with part number confirmation)
- Nengun Performance Toyota/Lexus parts catalogue
- MyLParts SC430 parts catalogue